Virtual heart valve

Abstract

A computational technique to construct a 3-D valve leaflet geometry. The invention pertains to methodology to construct a 3-D heart valve leaflet geometry using finite element analysis (FEA) to simulate the manual assembly process or, in other words, provide a virtual assembly process as an input to a subsequent simulated valve testing step. The simulated valves may be subjected to simulated cyclic valve opening and closings and the stress levels induced therein monitored. Simulated valve designs with lower principal stresses can then be selected for prototyping. Proposed valves can be subjected to cyclic fatigue stress testing under simulated physiologic conditions to study valve durability.

Description

RELATED APPLICATIONS(S)[0001]The present application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60 / 778,322, filed Mar. 2, 2006.FIELD OF THE INVENTION[0002]The present invention relates to methods and software for simulating a prosthetic heart valve and the dynamic forces applied thereto for the purpose of generating new and improved designs.BACKGROUND OF THE INVENTION[0003]Heart valve disease continues to be a significant cause of morbidity and mortality, resulting from a number of ailments including rheumatic fever and birth defects. Currently, the primary treatment of aortic valve disease is valve replacement. Recent statistics show that valvular heart disease is responsible for nearly 20,000 deaths each year in the United States, and is a contributing factor in approximately 42,000 deaths. Worldwide, approximately 300,000 heart valve replacement surgeries are performed annually, and about one-half of these patients received so-called mechanical he...

AI Technical Summary

Benefits of technology

[0008]The present invention utilizes computational methods to generate a 3-D bioprosthetic heart valve geometry. Starting from the drawing of a leaflet in flat form, a 3-D valve model is virtually created by simulating the valve assembly process in which the flat form leaflet is wrapped and mounted to the valve wireframe. The virtual assembly technique allows the precise determination of the 3-D geometry of the leaflets based on the leaflet flat pattern and the 3-D wireform assembly process. This technique enables designers to rapidly prototype valves with different leaflet and / or stent designs and to perform stress analysis before physical builds

Problems solved by technology

Heart valve disease continues to be a significant cause of morbidity and mortality, resulting from a number of ailments including rheumatic fever and birth defects.

However, these bioprostheses sometimes fail as a result of calcification and mechanical damage.

Particular challenges are encountered in numerical simulations of bioprosthetic heart valves, including nonlinear anisotropic leaflet mechanical properties, leaflet contact, and experimental validation.

In particular, experimental measurements of leaflet strain for validation are difficult to perform because of practical limitations in obtaining measurements very close to the leaflets and valve housing.

Moreover, prior design models are based on empirical methods of obtaining the leaflet geometry, which is difficult due to the free-form shape of the valve leaflets.

Physical measurements of an actual valve using, for example, a Coordinate Measuring Machine (CMM) or optical imager is cumbersome and prone to systemic in human errors, thus prohibiting efficient design evaluations.

Furthermore, because of an imprecise knowledge of surface definitions, computer-aided design (CAD) tools can only approximate valve leaflets surfaces, and important design features may be lost.

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